Characterization of Changes in Carbonaceous Support During Synthesis by Means of Coefficient Alfa

Abstract

Background: In the synthesis of materials composed of nano or microparticles supported on charcoal (or carbon), the carbonaceous support is often considered to be an inert material that acts as a physical support. However, the support may undergo significant chemical changes during synthesis that could influence the behavior of the synthesized material. This work proposes to use the coefficient alfa as an indicator of the changes that the support undergoes in a synthesis via impregnation. Methods: After developing a mathematical equation to obtain the value of the coefficient alfa experimentally, we calculated the value of the coefficient alfa in the synthesis of a composite material obtained by wet impregnation. In addition, we calculated the value of the coefficient alfa in a negative control group. Results: The coefficient alfa calculated for the material obtained by wet impregnation indicates that the carbonaceous support experienced significant mass loss during synthesis (p <0.0001). In the case of the negative control group, the coefficient alfa shows that significant mass loss (p <0.0001) also occurs when the support is treated with the solvent (instead of the particulate precursor solution). The mass loss of the carbonaceous support is significantly higher (p <0.0013) during the synthesis of the composite material than during the synthesis of the negative control group. Conclusion: The coefficient alfa is an indicator that allows one to verify the mass changes that the carbonaceous support undergoes during the synthesis of particulate material supported on carbon. Since a mass change implies a chemical modification of the support, these chemical changes should be taken into account when explaining the behavior of composite materials.